On the automorphism group of the countable dense circular order
نویسنده
چکیده
Let (C, R) the countable dense circular ordering, and G its automorphism group. It is shown that certain properties of group elements are first order definable in G, and these results are used to reconstruct C inside G, and to demonstrate that its outer automorphism group has order 2. Similar statements hold for the completion C.
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